This invention relates to a blade outer air seal (“BOAS”) system and, more particularly, to a blade outer air seal system having one or more replaceable members serving as the gas path surface. This scheme allows easy replacement of that portion of the BOAS that is routinely damaged from service usage.
Conventional gas turbine engines are widely known and used to propel aircraft and other vehicles. Typically, gas turbine engines include a compressor section, a combustor section, and a turbine section that cooperate to provide thrust in a known manner.
Typically, a blade outer air seal is located radially outwards from the turbine section and functions as an outer wall for the hot gas flow through the gas turbine engine. Due to large pressures and contact with hot gas flow through the turbine section, the blade outer air seal is typically made of a strong, oxidation-resistant metal alloy and requires a cooling system to keep the alloy below a certain temperature. For example, relatively cool air is taken from an air flow through the engine and routed through an intricate system of cooling passages in the seal to maintain a desirable seal temperature. Although effective, taking air from the engine air flow contributes to engine inefficiency by reducing engine thrust, and forming the seal with the cooling passages adds to the expense of the seal.
Accordingly, there is a need for a simplified and less expensive blade outer air seal that also reduces the need for cooling. This disclosed examples address these needs and provide enhanced capabilities while avoiding the shortcomings and drawbacks of the prior art.